In a conventional vehicle, when there is a probability that an own vehicle will collide with an obstacle around the vehicle, to avoid a collision, a collision avoidance device which controls traveling and issues a warning to drivers has been provided. As such a collision avoidance device, there is a steering stability controller disclosed in Japanese Published Unexamined Patent Application No. 2001-114081. This steering stability controller includes a collision judging device which judges whether a vehicle will collide with an obstacle by detecting the obstacle around the vehicle and a lane departure judging device which judges whether the vehicle will depart from a lane in which the vehicle is currently traveling by detecting the lane. In this steering stability controller even during steering stability control, when a collision judging device presumes that the vehicle will collide with an obstacle or depart from a lane, by stopping the steering stability control, the steering stability controller performs automatic control to avoid collision with an obstacle and departure from the lane.